grid 布局

grid-template

/* 值为关键词 */
grid-template: none;
/* 为 grid-template-rows / grid-template-columns */
grid-template: 100px 1fr / 50px 1fr;
grid-template: auto 1fr / auto 1fr auto;
grid-template: [linename] 100px / [columnname1] 30% [columnname2] 70%;
grid-template: fit-content(100px) / fit-content(40%);
/* 为 grid-template-areas grid-template-rows / grid-template-column */
grid-template: "a a a"
               "b b b";
grid-template: "a a a" 20%
               "b b b" auto;
grid-template: [header-top] "a a a"     [header-bottom]
                 [main-top] "b b b" 1fr [main-bottom]
                            / auto 1fr auto;
/* 为全局值 */
grid-template: inherit;
grid-template: initial;
grid-template: unset;